Water companies supplying Kent have published long-term investment plans on how they intend to ensure water is provided for customers amid increasing demand.

South East Water says it is planning to invest more than £4 billion in new infrastructure – including a new reservoir and desalination plant in Kent – and repairing the existing network.

Southern Water said it would spend "spend billions of pounds" over the next 50 years.

Both companies are trying to meet the twin challenges of a growing population and climate change.

Southern Water predicts if it did nothing, its water supply would fall short by 300 million litres per day by 2040, and by 500 million litres per day by 2075.

It aims to meet the challenge by reducing leakage by at least 50% by 2050 by replacing old water mains.

It also aims to persuade customers to use less water and wants to see an average usage of 100 litres per day.

The company intends to build two new reservoirs - with one planned for Havant Thicket in Hampshire - and to embrace new technology like water recycling and desalination.

Southern Water pledges greater cooperation with other water companies so that water can be transferred from one area to another more easily and when needed.

The company has 2.6 million customers across Kent, Sussex, Hampshire and the Isle of Wight.

Nick Price, Southern Water’s water strategy manager, said: "Water scarcity and shortfalls driven by climate change, population growth and increasing demand from industry are challenges we are ready for.

"This plan sets out the decisions we need to take to make sure there’s enough water for everyone in our region, now and in the future, and to protect and enhance our shared environment.

"We want to embrace new technology, taking actions to both reduce demand and increase supply. But we cannot achieve our goals without our customers and stakeholders. That’s why it’s important that we hear from as many members of the public as possible."

Southern Water’s Water Resources Management Plan is open for public consultation here. Comments can be made until February 20.

Meanwhile South East Water, which has 2.3 million customers across Kent, Sussex, Surrey, Hampshire and Berkshire, has produced its own vision for the next 50 years.

It says its will invest £2.2 billion in new infrastructure and a further £2.1 billion in reducing leaks and customer water use.

The company's Water Resources Management Plan can be viewed here.

The plan includes a proposal for a new reservoir at Broad Oak near Canterbury, a desalination plant at Reculver, and in East Sussex, a water recycling between the Peacehaven Wastewater Treatment Plant and Arlington, with a second reservoir at Arlington.

Lee Dance, the firm's head of water resources, said: "Our ability to supply water is under increasing pressure due to a growing population, changing climate and new laws to protect the environment.

"We’ve worked hard to create a regional solution which strikes a delicate balance between those pressures, while also protecting and enhancing the environment and adding value to society.

"These plans are very much long term and have taken into account the recent extreme weather we have experienced and the subsequent changing pattern we have seen in demand for water.

"It is also ambitious and wide-ranging and has been guided by extensive research, detailed data, customer involvement, and engagement with stakeholders and other interested parties.”